Allele frequencies. Frequencies of introduced alleles by position in the Ambystoma linkage map  and by study pond: (A) Bluestone, (B) Melindy, (C) Pond H, (D) Sycamore, (E) Toro. Red points are markers (from left to right) E23C06, E06E11, and E12C11. Vertical dashed lines separate linkage groups, which are plotted end to end from largest to smallest . The last marker is the mtDNA marker, placed arbitrarily at the end of the linkage map.